


Quantum Entanglement

by impossiblitiesandmiracles



Category: Dr. STONE (Anime), Dr. STONE (Manga)
Genre: Astronomy, Byakuya is a good dad, Character Study, Emotional Hurt/Comfort, Everyone Needs A Hug, Family, Family Feels, Father-Son Relationship, Fatherhood, Gen, I'm Bad At Summaries, Sad and Happy, Self Confidence Issues, Sort of happy ending, he thinks he’s a bad dad but he’s NOT, kind of, lots if feels, science duh, trust me the story isn’t as bad
Language: English
Status: Completed
Published: 2020-03-22
Updated: 2020-03-22
Packaged: 2021-02-28 21:22:16
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,158
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23253910
Author URL: https://archiveofourown.org/users/impossiblitiesandmiracles/pseuds/impossiblitiesandmiracles
Summary: Byakuya never really thought he’d make a very good dad. Now he had Senku, and that confirmed one thing: he was right. He was sure that he was the worst dad on the whole planet, but he was trying. He was really, really trying. Because honest to God, Senku was the best damn thing that had ever happened to him. So he was trying. And he supposed that even if he never got to space, earth was enough.
Relationships: Ishigami Byakuya & Ishigami Senkuu
Comments: 9
Kudos: 217





	Quantum Entanglement

**Author's Note:**

> Hello friends! This is my second fanfic for this fandom. I honestly just love the father son relationship that Senku and Byakuya have and I obviously had to add some angst. I couldn’t stop thinking about how their relationship would have evolved as time passed and how we never really talked about the fact that they’ll never get to see each other again :(
> 
> Anyway! Thanks for reading and let me know what you think!

_Blessed are the curious for they shall have adventures -lovelle drachman_

Alright let’s get one thing straight, Byakuya never asked to be a father. Personally he just figured he’d be a really crappy one so he never seriously considered it before. But the universe loves jokes, so here he is with Senku.

Senku Ishigami. Possibly one of the brightest minds in all of history, and definitely the smartest person in the room. The embodiment of intelligence and much too clever for his age, he was way too high maintenance for someone with as little experience as Byakuya. (Don’t get him wrong, he loved the kid. He was grateful as hell to have Senku, he just…he felt like the boy deserved better.) He was amusing to say the least, curiosity blooming from every corner of his mind and an imagination to follow suit. 

He had this greed in his eyes—he wanted to know everything, down to the smallest detail. The palace that was his mind was stocked with infinite shelves and once he filled those he would store knowledge in the hallways. Byakuya envied that. He used to know what that greed felt like. All astronauts have it, that look in their eye, that look that says the earth just isn’t quite enough and maybe not even the solar system would be.

Byakuya used to want to be an astronaut. But then he grew up, and the fire died, and the greed wilted, and he thought about how silly he must have been. He’d love another shot, he’d love to go to space, but the opportunity passed him by. And now he had a _kid_. He had Senku, and Byakuya thought that maybe the earth wasn’t so bad after all. 

“Dad!” Senku called. “Look! Look! I made a new paper airplane design.”

“Wow, great job kiddo,” he smiled. “Did you learn origami at school?”

“Huh? No,” Senku twirled the paper in his hand, “I taught myself. You know, if you fold the wings like this the plane is more aerodynamic.”

“Really…” to say he was shocked was an understatement. “Well, that’s pretty clever.” Senku grinned.

“Are you proud of me?”

“You know it.”

“C’mon, I’ll show you the other designs I made for real airplanes.”

Byakuya hadn’t signed up to be a dad, and he certainly hadn’t signed up to be a dad to a kid wonder like Senku. But, to tell the truth, he didn’t really mind all that much. He was a little worried about his ability to keep up with Senku’s ever evolving mind, but he figured that was a problem for the future. 

Still Senku found time to be a kid. He’d go outside and play in the puddles when it rained, he made friends at school, he colored outside the lines. Even though his mind was completely different than everyone else, he acted like he didn’t even notice. It was like he didn’t even know how smart he was just yet. 

And Byakuya loved him even more because of that. For a while he was worried that their bond would be strained because they weren’t biologically related, and then he was worried that Senku was way too smart and he’d somehow hold the kid back. Luckily neither seemed to be the case. Byakuya liked to think that their relationship was very good (and Senku wouldn’t argue).

He could feel it in his bones, like they had been brought together for a reason. It was like out of all the people in the world, the universe had chosen Senku specifically for him. They were on the same wavelength not necessarily intellectually, but atomically. They fit together. They were a fixed point in the universe and even across dimensions it would preside. Byakuya could feel it, they were entangled. 

Despite being infinitely smarter than himself at that age, Senku still had the same interests. It first showed around the age of four when he had asked why the stars changed.

“Changed?”

“Mhm,” the boy nodded, “They look different now. See those stars used to be over there, but they moved.”

“Actually,” Byakuya explained, “The earth is the thing that moved. Or turned to be more accurate. The earth spins on an axis which causes day and night. It also orbits around the sun which changes its place in the sky, so we see different stars.”

“Oh.”

“Pretty cool, huh?”

“Yeah!” Senku cried, “Tell me more about the stars! Please?”

“Sure.” Byakuya lifted Senku so the kid could sit on his shoulders. Then he began to point at the stars and talk about the constellations and how people had learned how to navigate the globe by charting them. Senku rested his chin on Byakuya’s head, eyes glued on the sky, and absorbed every bit of knowledge his dad had to share. 

From then on he showered Senku with stories of outer space. The boy lit up with an immediate love; of course the kid would latch onto the idea of exploring the universe, who wouldn’t?

“I’m going to be an astronaut,” Senku told him one night. Byakuya smiled and gave his son a thumbs up.

“You'll be the best one ever,” he said. “You know, I used to wanna be an astronaut.”

“Really?”

“Yup,” he nodded. 

“Then why aren’t you in space?” Senku asked.

“Maybe I don’t want to go anymore.”

“How come?”

“I don’t know,” Byakuya shrugged, “I guess I found something on earth worth staying for.” Senku scrunched his face in confusion but before he could press any further Byakuya kissed him on the forehead, “Goodnight, kid.”

Time continued on, the world changed, and Senku only got smarter. But his goals didn’t change. All he talked about was going to space. All he talked about was rocket science and astrophysics and things way beyond his years that he seemed to comprehend better than any adult could.

And when Senku asked him again why he didn’t want to go to space anymore, Byakuya made the mistake of telling him it was because he couldn’t swim. The boy seemed to take that as a challenge.

Byakuya had always known Senku was intelligent, he just didn’t realize he was intelligent enough to build electrical impulse nerve gear at the age of six. Clearly he had underestimated Senku—a mistake he will never make again, mind you. 

He came to this realization when Senku, who had only just begun primary school, came to him with an electro muscular stimulation machine that he had built with the help of his friend Taiju. It was supposed to teach him how to swim. Byakuya, to say the least, was beyond surprised. He had never actually expected anything to come of their promise; clearly, Senku had other ideas. 

“You said you didn’t know how to swim,” Senku said, “So now you can learn.”

So here he was with a borderline unhealthy amount of volts running through his muscles, learning how to swim. Because that was what he had told Senku was holding him back. 

_I don’t know how to swim_ , he had said. But what he meant was: I’d miss you too much. 

(And sadly, no science machine could fix that.)

When Senku got to middle school he started to build rockets. He was testing mathematical theories and the laws of aeronautical engineering while most kids were just trying to figure out how to solve for “x”. Byakuya was in the space program by now, with no small amount of effort on Senku’s part, so he was too busy to tell space stories and watch as Senku tinkered about with robots. Despite that though, he still made an extraordinary effort to help Senku in any way that he could—he’d tell him all the details of his job and even bring home sample calculations and spare pieces of material for him. 

Because no matter how busy Byakuya got, he’d never be too busy for Senku. 

What kind of dad would he be if he didn’t inspire his son? What kind of man would he be if he didn’t go to every effort to repay the genius who helped him achieve his goal? [Answer: a pretty shitty guy on both accounts.] So obviously he did anything he could to help Senku. He may not be a genius but he sure as hell wasn't an idiot. 

And Byakuya thought he was getting a pretty good handle on this dad thing. Nobody had died or been seriously injured so far, and he considered it a win. He worked tirelessly that winter to be able to buy Senku an absolutely amazing Christmas present just like the good dad he was, and it was a total success. So after nailing Christmas that year, and the birthday that followed, he was becoming very confident in his fathering abilities. Byakuya found himself wondering what he had been so afraid of. 

Then Senku got sick—like full on throwing up and too high temperature kind of sick—and he was reminded that oh yeah, that’s what he was afraid of. 

“I don’t feel very good,” Senku had said early that evening.

“Want me to get something from the store to help?” He offered.

“No, it’s probably just something I ate. I’m going to go lay down for a little bit.”

“Alright, let me know if you need anything.”

“Mhm.”

He had watched the young teen disappear up to his room. And he hadn’t been worried, that is, until four hours had passed and Senku had yet to make a reappearance. So like the diligent parent that he was he went to check on him.

Senku’s room was dark and the boy was wrapped up in a blanket facing the wall so Byakuya didn’t notice the flush on his cheeks.

“Senku, you should wake up now,” he said, “If you sleep much longer you’ll miss dinner and throw off your sleep schedule.” He moved to pull the covers off of the teen, but the only response was a faint groan. Byakuya noticed the raspy breathing.

“Senku—” he placed the back of his hand on the kid’s forehead. “Shit.” 

“I really…don’t feel well…” Senku groaned, turning over and pulling the blanket up to his chin.

“You have a high temperature,” Byakuya worried aloud, “And your voice is rough, are you having trouble breathing?” Senku shook his head, thought for a moment more and then shrugged.

“No…not really,” he sounded unsure, “But my stomach hurts. I think I’m gonna—”

Suddenly Senku launched himself out of bed and towards the bathroom. He retched into the toilet, emptying his stomach of everything he’d eaten that day. Byakuya stood in the doorway, unsure. The boy continued to dry heave for a few more minutes before his shoulders slumped. He was breathing heavy and looked absolutely exhausted. 

Byakuya wasn’t entirely sure what to do, Senku had never been this sick before, did he need a hospital? Probably not yet, but if his fever got any higher…Byakuya took a deep breath, then moved the rest of the way into the bathroom.

“Let’s get you back to bed,” he placed a hand on Senku’s back and another around his shoulders, guiding him back to bed. “Just…just lay down. I’m going to go get you some medicine—do you want water? I should probably get you some water, and maybe another blanket? What else…” He trailed off.

“I’m fine,” Senku protested, “Just tired. I’ll sleep it off…probably just…something I ate…”

“Idiot,” he said. “You are not okay. I’m gonna go get some stuff, I’ll be right back. Stay- stay here, alright?” Byakuya hurried out of the room, his mind racing a mile a minute. What was he going to do? He’d never been very good with sick people, and a sick kid? Forget about it. He was in way too far over his head. 

(Though, he would like to make a point that he only panicked for an hour before he was able to pull himself together.)

Finally he got his bearings. One of his friends worked at a convenient store so he asked him to swing by with some supplies. He also called off the next few days of work. Once he had a plan the situation was much easier to handle. Senku was quite independent and Byakuya felt an odd sense of worthiness wash over him at the prospect of finally being able to take care of Senku like normal parents do. 

He tried to remember what his parents did for him when he had been sick, and he did the same. 

So the next week was chicken noodle soup and cold compresses and lots of rest. Surprisingly it seemed to work, and Senku could sleep through the night after a few days, and then he was able to keep down real food. He was up and moving after a week, back to his normal self shortly after. He was fine. Senku was fine. 

There was an odd sense of “I did it!” that Byakuya chalked up to his insecurities about parenting. Though he was having less of those moments as time went on, he was definitely getting the hang of it.

He breathed a sigh of relief. And from then on he was a total health nut because by god Byakuya was absolutely _not_ going through that again.

He remembered the day they told him he was going to go to space. It was the happiest day of his life. Byakuya had dreamed of going to space his entire life and he had lost hope that it would ever actually happen. But here he was, a full fledged astronaut on his way to the international space station. 

Since it was his last night on earth he wanted to do something special for Senku, as a sort of goodbye and also a thank you. So he hurried home, Senku would be a little late because of the science club, but he wanted to catch the kid before he retreated to his room for research.

Byakuya ordered in ramen and set the table. Senku was home a few minutes past five o’clock.

“Hey kid!” He called. “Come sit down. I ordered ramen.”

“What’s up, old man?” Senku raised an eyebrow, “I have research to do.”

“Just come sit with me, would you?” He rolled his eyes, “Call it a goodbye for your dear old dad before he goes off to space.” Senku scoffed.

“That’s what astronauts are supposed to do.”

“Awe c’mon. Aren’t you going to miss me?”

“I’ll be too busy making scientific breakthroughs.”

“Sit down,” Byakuya told him. “A dinner at the table won’t kill you.” Senku gave him a doubtful look but did as he was told.

Their relationship had evolved into sarcasm and read-between-the-lines affection so it was sort of strange to be making such a big deal out of this. He’d been gone before, on international missions and other training camps in preparation for the launch, but this time was different. He was going to be awfully far away and for some reason a part of him wanted to say goodbye, even if it wasn’t really their thing.

“You know, astronauts go to space all the time,” Senku said, slurping ramen, “Don’t expect me to say goodbye to you every time I go to space.”

“Hm,” he laughed. “Alright. Just for this time then, let me be sentimental.” Senku scoffed but his eyes held no annoyance. Byakuya smiled. 

“Let’s go on a walk,” Byakuya said. “Consider it astronomy research,” he added before Senku could make up an excuse not to go. So they finished dinner and then took a very old route that they used to walk when Senku was little. They had a competition to see who could name the most constellations (it was a tie). And finally they made it to the top of the hill where Senku had first shown interest in the stars. 

“I’m gonna be pretty far away tomorrow,” he said to break the silence.

“Not that far away, when you really think about it,” Senku shrugged. “Only 254 miles. You were farther away when you went to America.”

“I guess so, but…” Byakuya paused, “We won’t be on the same planet anymore. That’s kind of strange to think about.”

“Are you chickening out?”

“Wha—no way!”

“Good,” Senku grinned, “Because when I finally get to space it wouldn’t feel like much of a win over you if you had chickened out. I’m going to be the best astronaut ever, that includes you. So you better make it a challenge, old man.”

“Whatever you say,” he laughed. “What kind of souvenir do you want?”

“Souvenir? What am I, a grade schooler?”

“So a moon rock?”

“No!” Senku looked offended, “It’s gotta be something cooler than that.”

“Like what?”

“I don’t know,” he shrugged, “Something useful.”

“I’ll see what I can do,” Byakuya smiled. 

“Better not disappoint,” Senku said, “When you get back to Earth I’ll have made a scientific breakthrough. You’ll be so proud you’ll cry.”

“I never cry.”

“You will this time, ten billion percent,” he assured him. Byakuya smiled fondly and ruffled Senku’s hair. 

_I’m already proud of you_ , he thought. _So very proud of you, Senku, you don’t even know._

It was everything he had imagined it would be. It was every bit as wonderful. Space was truly magnificent, Byakuya belonged there. He used to think that space was made for him, that the stars were specifically aligned to inspire him, then he met Senku. And he realized that the universe was not made to touch him (though it did all the same), instead it had been created to nurture this genius of a human, and he had been given the opportunity to help. Byakuya could see it, he could see the way Senku looked at the stars and how the universe seemed to gaze back.

He wouldn’t have it any other way. He’d play his part with joy, and he’d love every minute of the time he got to spend with his son. Byakuya was going to be sure to bring back something worthwhile.

And it was a perfect few days. Until it wasn’t. 

Byakuya could almost feel the moment something was wrong. A green light burst forth and covered the earth. Everyone on the space station was mesmerized and it was as if space time stood still for a few moments. And then chaos. They were radioing all the ground stations trying to get someone—anyone to answer them. 

When there was no response it became abundantly clear that something had gone very wrong. And they all had the same terrifying thought: what if they were the last humans alive? Of course they didn’t have time to dwell on this, and even if that was the case they sure as hell didn’t have time to stay up here and pout about it.

A plan was quickly formed, and carried out. 

Then they were back on earth. No people besides them walked the surface, and not even birds flew in the sky. Byakuya wished desperately that he had paid more attention to what exactly it was that Senku was researching. And there it was, the crushing weight on his chest—Senku was stone too. Although there was no doubt in his mind that his son was still alive, Byakuya was still hit with a wave of helplessness.

He had to figure out a way to help Senku when he woke up, because he _would_ wake up. No telling how much time will have passed, Byakuya doubted he’d be around for it, so this gift he was to leave behind had to be something that could be preserved. 

He tried to think like Senku, what the boy would need, what would be helpful, anything along those lines. Finally, he got it. 

It was years after that when they had established a settlement and been able to put the gift together. Byakuya could only hope it would be of some use to Senku in the future, whenever that may come. 

So they lived on—not the same as before, never the same, but still they lived on. They never forgot their loved ones, they never forget what the world meant to them. 

Byakuya felt a strange guilt. If he hadn’t gone to space, if only he had stayed with Senku, would anything have changed? No, he supposed, perhaps then they would both be stone. And that was no use to anybody. So he thanked the universe, though solemnly, that he had been in space. 

There was another strange feeling too, one of purpose. Like it was all meant to happen this way. And even though he was a subject to flesh and time still passed, he felt as though he was connected to Senku. They were on the same wavelength, and even if they were a universe apart they would always be connected, somehow. 

This connection, this relationship they had to one another felt much bigger than anything Byakuya could wrap his mind around. It was something he didn’t quite understand, though it felt rather like some theory Senku would have been able to explain. Nevertheless, it helped calm his mind that he and Senku were intertwined by their very beings.

“Sorry, kid,” he said. “Guess you’ll have to wait a little longer, but I hope it’s worth your while.”

  
Senku had never been a fan of fairy tales, he was a man of science. Even when he was little he ten billion percent preferred a scientific theory over a fairy tale. He always insisted that Byakuya tell him an accurate depiction of the stars, instead of those silly stories. 

It had been 3700 years since Senku had heard his dad's voice. So when they had uncovered the record and finally gotten it set up, he couldn’t help the smile that split across his face when Byakuya started speaking. And even though it was sort of silly, and he had chosen to record history in the form of a hundred fairy tales, Senku found that he didn’t really mind all that much. 

He figured stories weren’t all that bad. 

(And he supposed that the things Byakuya had left behind weren’t bad either. He’d kept his promise of not disappointing.)

And then, later, they had found the escape pod the astronauts had returned to earth in. All the minerals and things left perfectly preserved inside of it. There was a small sadness that ebbed in Senku’s chest because he wished he was able to thank his dad for all that he did. 

He supposed the best thank you would be to restore the world, and finally get to space. So he decided to focus on that instead of the ache of subdued grief that settled in his stomach. 

In all honesty he was just a little disappointed, and a little angry. He wanted to be able to show Byakuya all the great things that he invented. He wanted to be able become an even greater astronaut than his dad. But there was no point in having a competition with the dead. 

Senku was sort of upset that he’d never get to see the look on Byakuya’s face when he finally got to space. He knew there was no point in regretting the past, he couldn’t do anything to change it. 

“What is that?” Gen had asked when he had pulled the stone from the capsule.

“The holy grail of minerals,” Senku explained, “Just about the hardest stone to find anywhere and absolutely essential to furthering our kingdom of science: platinum.” 

He wondered if Byakuya had known just how important this stone was, then he decided that _of course_ he had known. That’s why he’d left it behind. Byakuya had always had a way of knowing exactly what Senku needed—he had always chalked it up to fatherly instincts; now, he was beginning to think it was a little more than that. 

Senku was angry; angry that he’d never get to show Byakuya just how great of an astronaut he was going to become. But he was also sad; sad because he’d never get to show Byakuya anything ever again, he’d never get to make him proud again. And hadn’t that always been the point?

(Of course Senku had a genuine love of science and exploration, and he did it mostly for himself because it was fun, but there had always been a little bit of it that had been for Byakuya too.)

“Can you see me, old man?” Senku asked. “Are you proud of me?” 

As if in response a shooting star crossed the sky just then, quickly racing out of sight. 

The stars wept for them—the prodigy and the astronaut who were forever entangled not only to each other, but into the fabric of space itself. The father and the son who would only ever be reunited in memory. 


End file.
